At the end of March, the annual meeting of the American Association for Cancer Research (AACR), to be held March 29 – April 3, 2019, is expected to covers the latest discoveries across the spectrum of cancer research—from population science and prevention to cancer biology, as well as translational research and clinical studies.
The annual meeting will also included updated about survivorship and advocacy, and highlights the work of the best minds in research and medicine from institutions all over the world.
Among the latest research results to be presented during the upcoming AACR meeting are pre-clinical data on BA3071, a novel conditionally active CTLA-4 inhibitor.
The CTLA-4 pathway is a key immune checkpoint pathway that provides a downregulating signal to T cells. Although inhibition of CTLA-4 has been shown to significantly improve the antitumor response, it may also lead to immune attack of healthy cells. To minimize on-target off-tumor toxicity, BioAtla applies its proprietary CAB technology with the intent to activate binding to the CTLA-4 receptor preferentially on T cells in the tumor microenvironment.
The data to be presented at AACR indicate that the company’s CAB-CTLA-4 molecule may have a superior safety profile when used in combination with PD-1 inhibitors and allow increased dosing levels to achieve superior efficacy to current anti-CTLA-4 therapy as a single agent or in combination with other anti-cancer therapies including immuno-oncology agents.
The BA3071 IND filing is planned for mid-2019. A Phase I/II multi-center, open-label study designed to evaluate the safety, tolerability, pharmacokinetics, immunogenicity and antitumor activity of BA3071 alone and in combination with a PD-1 inhibitor is anticipated to start in later in 2019.
The second investigational agent is BA3181, a novel conditionally active EpCAM targeted antibody-drug conjugate or ADC (CAB-EpCAM-ADC), being developed by San Diego-based biopharmaceutical company BioAtla®.
EpCAM is expressed at high levels exclusively in epithelia and epithelial-derived neoplasms, making it a suitable target for many important solid tumor types and cancer stem cells. EpCAM expression on normal tissues limits its utility as a target for therapeutic antibodies and ADCs due to the potential effects on normal epithelial throughout the body. Using our CAB technology, BioAtla has developed CAB antibodies to EpCAM that reversibly bind to recombinant EpCAM and EpCAM expressing cells under select conditions that are present in the tumor microenvironment but not in normal tissues.
In vitro and in vivo efficacy data for several anti-EpCAM antibodies and ADCs will be presented and suggest that conditionally active EpCAM ADCs generated using the CAB technology provided drug candidates, including BA3181, that have the potential to have an increased safety margin and therapeutic index in the clinic.
The company’s novel CAB-CTLA-4 and CAB-EpCAM-ADC programs are designed to yield conditionally active therapeutics (antibodies as well as other biologics) that can be activated or inactivated under defined physiological conditions (e.g., pH, oxidation, temperature, pressure, presence of certain ions, hydrophobicity and combinations thereof) both outside and inside cells.
The company’s patented Conditionally Active Biologics™ (CAB) technology takes advantage of the unique microenvironment associated with different diseases and tissues.
These differences can, for example, result from differences in metabolism between diseased and normal, healthy, tissue.
For example, in cancer the unique cell metabolism described by Otto Warburg, referred to as the “Warburg effect” (i.e., anaerobic glycolysis in the presence of oxygen in tumor cells) [*] contributes to a characteristic microenvironment that activates antibodies when they are in close proximity to a tumor, and reversibly inactivates an antibodies if they drift away from the tumor.
“These new data showcase the capabilities of our proprietary CAB technology, which we believe will expand the number of druggable protein targets and maximize both potency and safety in combination therapies, antibody drug conjugate (ADC) medicines, bispecifics and other targeted therapy formats for cancer treatments,” explained Jay M. Short, Ph.D., Chairman, Chief Executive Office and co-founder of BioAtla.
“We are particularly excited by these new preclinical data for our novel CAB-CTLA-4 program as a single-agent or in combination with checkpoint inhibitors. This novel CAB has the potential for an improved safety margin and therapeutic index thereby improving this important cancer therapy,” added Scott Smith, President of BioAtla.
“These preclinical data suggest that our CAB technology may effectively address the issue of on-target off-tumor toxicity and allow leveraging the widely expressed and promising EpCAM target for cancer therapy,” Smith further noted.
In addition to the above programs, BioAtla has two programs currently in Phase I/II clinical trials, BA3011 a novel conditionally active AXL-targeted antibody-drug conjugate (CAB-AXL-ADC) and BA3021 a novel conditionally active ROR2-targeted antibody-drug conjugate (CAB-ROR2-ADC).
|Title||Potent CAB CTLA-4 antibody to reduce immune side effects and toxicities associated with single agent and combination cancer immuno therapies|
|Session||Rational Combinations of Immunotherapy|
|Date/Time/Location||April 1, 2019 / 3:00PM – 5:00 PM|
|Presenter||William Boyle, Ph.D.|
|Title||Novel conditionally active biologic (CAB) antibody targeting EpCAM demonstrates anti-tumor efficacy in vivo|
|Session||New Anticancer Agents|
|Date/Time/Location||March 31, 2019 / 1:00 PM – 5:00 PM / Exhibit Hall B, Poster Section 14 / Poster Board Number: 17|
 Otto AM. Warburg effect(s)-a biographical sketch of Otto Warburg and his impacts on tumor metabolism. Cancer Metab. 2016 Mar 8;4:5. doi: 10.1186/s40170-016-0145-9. eCollection 2016. [PubMed][Article]
[*] In 1972 Efraim Racker, in his publication on the bioenergetics of tumor growth coined the presence of high aerobic glycolysis in tumors as the ‘Warburg effect’.
Last Editorial Review: Match 2, 2019
Featured Image: Annual Meeting AACR. Courtesy: © 2010 – 2019 AACR. Used with permission.
Copyright © 2010 – 2019 InPress Media Group. All rights reserved. Republication or redistribution of InPress Media Group content, including by framing or similar means, is expressly prohibited without the prior written consent of InPress Media Group. InPress Media Group shall not be liable for any errors or delays in the content, or for any actions taken in reliance thereon. ADC Review / Journal of Antibody-drug Conjugates is a registered trademarks and trademarks of InPress Media Group around the world.